Characterization of ultrasonicated and ozonated oat 1, 4-β-D-glucan

Abstract

Oat 1, 4-β-D-glucan is renowned for its physiological benefits and industrially relevant properties. However, its high molecular weight and viscosity limit its industrial applications. To enhance its functional and structural properties, oat 1, 4-β-D-glucan was modified using ultrasonication (US) and ozonation (OZ), and its functional, structural, thermal, and rheological properties were characterized. The yield and recovery of 1, 4-β-D-glucan were 4.74 % and 81.6 %, respectively. Molecular weight decreased from 1450 × 10³ Da (native) to 52 × 10³ Da (OZ-II). Hydrodynamic particle size reduced from 2510.8 nm (native) to 156.3 nm (OZ-II), with a polydispersity index and zeta potential of −10.8 mV indicating enhanced uniformity and stability. FE-SEM showed structural disruption in US-treated samples and porosity in OZ-treated samples. DSC analysis indicated increased thermal stability in OZ-II, with the highest onset temperature (29.71 °C) and lowest enthalpy change (107.52 J/g). The frequency sweep and shear test showed that all samples exhibited shear-thinning property and lowest viscosity values were observed for OZ-II. FTIR spectra confirmed structural modifications, with increased peaks at 1720 cm⁻¹ (CO stretching) in OZ-treated samples, indicating oxidation. Additionally, X-ray diffraction analysis revealed a reduction in crystallinity index from 32.2 % (native) to 29.4 % (OZ-II), attributed to disruption of the crystalline regions by ozone treatment. These findings demonstrate that US and OZ modifications significantly enhance the functionality and processing suitability of 1, 4-β-D-glucan, providing valuable insights for its industrial application.